1. Field of the Invention
This invention relates to novel peroxy esters, specifically 1-cyclohexyl-1-methylethyl peroxy esters, polymerization initiators having the peroxy esters as a principal component and used for vinyl monomers such as, for example, (meth)acrylic esters, methyl methacrylate, vinyl chloride and vinyl acetate, and curing agents having the peroxy esters as a principal component and used for unsaturated polyester resins.
2. Prior Art Statement
Heretofore, methods for using various organic peroxides and azo compounds such as azo-isobutyronitrile ("AIBN") as polymerization initiators for vinyl monomers either alone or in combination with copolymerizable vinyl monomers or as curing agents for unsaturated polyester resins have been known to the art.
As initiators of low-temperature polymerization of such a monomer as vinyl chloride or a derivative thereof, for example, the peroxy esters such as cumyl peroxy neodecanoate (CND) and paramenthane peroxy neodecanoate (PMND) whose carboxylic acid moiety has a tertiary .alpha.-carbon are disclosed in Japanese Patent Public Disclosure SHO 58(1983)-120611. As polymerization initiators in the polymerization of unsaturated monomers such as styrene and methyl methacrylate or in the copolymerization of these unsaturated monomers in combination with other copolymerizable unsaturated monomers and as curing agents for unsaturated polyester resins, benzoyl peroxide (BPO), t-butylperoxy-2-ethyl hexanoate (t-BO), pinane peroxy-2-ethyl hexanoate (PEO), or paramenthane peroxy-2-ethyl hexanoate (PMO) has been used either alone or in combination with a peroxide which is active at a higher temperature. AIBN has been used as a polymerization initiator for vinyl acetate.
The method for polymerizing a monomer such as vinyl chloride or a derivative thereof by the use of CND and PMND as a polymerization initiator, however, imparts the produced polymer with the offensive odor of the polymerization initiator itself or the decomposition product thereof. The polymerization of styrene or methyl methacrylate and the curing of an unsaturated polyester resin by the use of BPO, t-BO, PEO, or PMO are inferior in productivity due to slow polymerizing and curing speeds and low in quality due to impregnation of the polymer or cured product with the offensive odor. The polymerization of vinyl acetate by the use of AIBN causes undesirable coloration of the produced polymer. There is thus a need for a polymerization initiator and a curing agent which produce high polymerizing and curing speeds and yield a polymer and a cured product which are not imparted with unwanted odor or color. The present invention aims to meet this need.